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llvm-project/llvm/test/CodeGen/X86/eh-frame-unreachable.ll

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Don't emit CFI instructions at the end of a function When functions are terminated by unreachable instructions, the last instruction might trigger a CFI instruction to be generated. However, emitting it would be be illegal since the function (and thus the FDE the CFI is in) has already ended with the previous instruction. Darwin's dwarfdump --verify --eh-frame complains about this and the specification supports this. Relevant bits from the DWARF 5 standard (6.4 Call Frame Information): "[The] address_range [field in an FDE]: The number of bytes of program instructions described by this entry." "Row creation instructions: [...] The new location value is always greater than the current one." The first quotation implies that a CFI cannot describe a target address outside of the enclosing FDE's range. rdar://problem/26244988 Differential Revision: https://reviews.llvm.org/D32246 llvm-svn: 301219
2017-04-25 02:45:59 +08:00
; RUN: llc < %s -mtriple=x86_64-apple-darwin | FileCheck %s
; Test that we don't emit a row that extends beyond the FDE's range_size.
;
; CHECK: movq %rsp, %rbp
; CHECK-NEXT: .cfi_endproc
; CHECK-NOT: .cfi
define void @f() #0 {
unreachable
}
attributes #0 = { "no-frame-pointer-elim"="true" }